Inclusion Criteria:

• Signed Informed Consent
• Male or female 18 years of age or older
• Documented, endogenous plasma AAT levels < 11 µM (< 80 mg/dL), either obtained from the medical history or, if not documented, plasma AAT measured after 28 day washout of any prior replacement therapy
• Forced expiratory volume at 1 second (FEV1) that is >= 50% of predicted, measured 30 minutes after a short-acting inhaled bronchodilator
• Arterial oxygen percent saturation (SaO2, measured using room air) within the normal limits for the individual study site
• For subjects receiving an inhaled corticosteroid, inhaled or oral β-2 agonist (e.g., albuterol via metered dose inhaler [MDI]) or inhaled anticholinergic bronchodilator (e.g., ipratropium bromide), or oral PDE (phosphodiesterase) inhibitor, treatment on a stable dose for at least 14 days prior to enrollment
• For any female of childbearing potential, a negative urine test for pregnancy within 3 days prior to enrollment and agreement to employ adequate birth control measures for the duration of the study
• No clinically significant abnormalities detected on a 12-lead electrocardiogram (ECG) performed at the screening visit
• Laboratory results obtained at the screening visit, meeting the following criteria:
• Serum aspartate transaminase (AST) and alanine transaminase (ALT) <= 2 times upper limit of normal range (ULN)
• Serum total bilirubin <= 2 times ULN
• < 2+ proteinuria on urine dipstick
• Serum creatinine <= 1.5 times ULN
• Absolute neutrophil count >= 1500 cells/mm3
• Hemoglobin >= 10.0 g/dL
• Platelet count >= 100,000/mm3

Exclusion Criteria:

• Clinically significant pulmonary impairment, other than emphysema and/or chronic bronchitis
• Moderate to severe bronchiectasis
• Clinically significant cardiac, hemostatic, or neurologic impairment, or other significant medical condition that, in the opinion of the investigator, would affect subject safety or compliance
• Psychiatric or cognitive disturbance or illness, or recreational drug/alcohol use that, in the opinion of the investigator, would affect subject safety or compliance
• Acute exacerbation of emphysema within 28 days prior to the screening visit
• Pregnancy or lactation
• Known history of allergy to yeast products
• Medical history precluding the use of epinephrine or other rescue medication for treatment of anaphylaxis
• Prior history of adverse reactions to the local anesthetic, sedative, BAL procedure, or pre-medication employed at the study center
• Use of oral or parenteral glucocorticosteroids, or alpha 1-antitrypsin replacement therapy within 28 days prior to baseline BAL, or any use planned during the study. However, the subject may enroll provided that a) consent is given to undergo a 28-day washout of the replacement or steroid therapy, and b) no study procedures are done until the washout is completed.
• Use of another investigational drug or investigational device within 28 days prior to baseline BAL
• Any upper or lower respiratory infection within 28 days prior to baseline BAL
• Having received a lung or liver transplant